NEW YORK (AP) – The number of U.S. children in foster care is climbing after a sustained decline, but just five states account for nearly two-thirds of the recent increase. Reasons range from creation of a new child-abuse hotline to widespread outrage over the deaths of children who’d been repeatedly abused. Addictions among parents are another major factor.

The most dramatic increase has been in Georgia, where the foster-care population skyrocketed from about 7,600 in September 2013 to 13,266 last month. The state is struggling to provide enough foster homes for these children and keep caseloads at a manageable level for child-protection workers.

Along with Georgia, the states with big increases are Arizona, Florida, Indiana and Minnesota. According to new federal figures, the nationwide foster-care population went up from 401,213 to 427,910 between September 2013 and September 2015, and these five states accounted for 65 percent of that rise.

In all five, a common factor driving the increase has been a surge of substance abuse by parents.

In Florida, for example, officials said that a crackdown on abuse of prescription drugs has prompted more parents to turn to heroin and other illegal opioids, leading to the removal of their children from home. Florida’s foster-care population increased by 24 percent between 2013 and 2015; nationally the increase was less than 7 percent.

In Georgia, parental substance abuse now accounts for about 38 percent of foster care entries. That was the focus of a recent briefing in the state Senate, where a county child-welfare official reported, “We recently rescued an 8-year-old boy who graphically disclosed being raped on a regular basis in his home where he lived with his father in a ‘drug house'”

Georgia child welfare officials cite two factors beyond drugs.

One is a centralized statewide child abuse hotline, created in 2013 to replace the 159 different hotline numbers that were used in Georgia’s counties. Since then, abuse reports have increased by 30 percent to more than 110,000 per year, and the number of abuse investigations has nearly doubled.

Another factor has been public outrage after some highly publicized cases in which children died from severe abuse even though caseworkers had prior indications that they were at risk. Heaven Woods, for example, was the subject of an abuse report in May 2014 – the ninth involving her family in the 5-year-old’s lifetime – but there was only a cursory investigation, and she was beaten to death three weeks later.

Bobby Cagle, who took over Georgia’s Division of Family and Child Services after that incident, toughened the procedure for investigating alleged abuse. He also helped add more than 600 new positions for his agency, but division spokeswoman Susan Boatwright said personnel problems persist because of high turnover linked in part to starting salaries for caseworkers that range as low as $28,000.

“They’re leaving because they can make more money,” she said. “If we could hang onto people, we’d be in better shape.”

As in Georgia, the surge of the foster-care population in Minnesota is due in part to a high-profile child fatality – a 4-year-old boy named Eric Dean who died in 2013 after repeated abuse by his stepmother. In 2014, the Minneapolis Star-Tribune ran an in-depth story reporting how Eric’s plight drew little scrutiny despite 15 separate abuse reports being lodged with social workers.

In response, Gov. Mark Dayton ordered closer oversight of child-protection decisions and formed a task force that recommended dozens of steps to place more emphasis on child safety.

As a result, Minnesota is now formally investigating a higher percentage of the child abuse reports received by its hotlines. According the state Department of Human Services, the volume of those reports has increased by 50 percent since early 2014, and state’s foster-care population has risen by about 33 percent.

“Now we’re erring on the side of removing the child from home, rather than doing everything we can to preserve the family,” said Lilia Panteleeva, executive director of the Children’s Law Center of Minnesota.

She said there were good reasons for the shift, but expressed concern about a dearth of resources to be sure the children removed from their families were being cared for by well-trained foster parents and getting access to quality support services.

“We’re dealing with this huge tsunami with very little direction from the legislature,” she said.

According to the new federal figures, Indiana had the second biggest surge in foster children after Georgia – rising by 37 percent from 12,382 in 2013 to 17,023 in 2015.

James Wide of Indiana’s Department of Child Services said parental substance abuse was a major factor.

“The increase in heroin, meth, cocaine and prescription medication abuse, compounded by mental health issues, has brought many more children into our system,” he said in an email. “Sadly, many adults are addicted, and their disease is keeping them from caring for their children.”

In Arizona, where the foster care population has been rising steadily for six years, the child welfare system has been buffeted by a series of major problems – including burdensome caseloads for child-protection workers, cutbacks in services to vulnerable families, and a sharp increase in the number of reports of child maltreatment.